(Medical):Age 22
He contracted smallpox but was not physically scarred by it.
Age 33
He has his first attack of malaria. This disease plagued him for the rest of his life.
Age 35
Suffered a serious jousting accident, after which he began complaining of chronic migraine headaches.
The extraordinarily painful leg ulcers began at about this time. He would suffer with them for the rest of his life. They eventually crippled him.
In his late 30's
Henry underwent a major personality change. He had always been wise and benevolent. But, slowly, he turned into an irrational and volatile ogre. His enemies could expect no mercy; neither could his friends, to say nothing of his wives.
Age 44
Henry suffered a severe jousting accident and was unconscious for about two hours. After recovery he continued to exhibit his usual fits of blind rage. But now they were aggravated by acute insomnia, painful sore throats, and recurrent, severe migraine headaches.
Henry became prematurely gray and abnormally obese. It was reported that in one 4 year period his waist increased by 17 inches. They say 3 of the biggest men to be found could fit into his doublet at one time.
Age 45
He developed a strange growth on the side of his nose.
Age 49
He probably became sterile or impotent.
Age 54
He could hardly walk and was carried everywhere by sedan chair. He became increasingly absentminded, often issuing opposing orders on succeeding days.
Age 55
He spent the last 8 days of his life in bed. He was too weak to lift a glass of water to drink.
He died amid the horrendous stench of his bursting leg ulcers.
Lord Montague had predicted some time before, that Henry's "leg will kill him, and then we will have jolly stirring"

Someone once prophesied that "...dogs will lick his bones as they did Ahab's." His body was being transported to Windsor for burial, and sometime during the night the coffin burst open. When the sentries found him, dogs were licking his remains.

Conclusion - The Cause of Death
His first two wives, Katherine of Aragon, and Anne Boleyn, suffered a number of miscarriages and stillbirths. None of his offspring had children. I agree there could be other reasons for both of those facts, however, added to Henry's medical history, I say they point to the inescapable conclusion that Henry VIII died of Syphilis.